New Year already setting drought record in Mendocino County

Just two weeks in, officials are already calling 2014 Mendocino County's driest year on record, and saying no relief is expected in the near future.

Less than a quarter-inch of rain fell in the Ukiah Valley Saturday, according to National Weather Service meteorologist Jeff Tonkin. That 0.18 inches is Ukiah's only rainfall this year, and it's less than a drop in the bucket to the valley's usual 37 inches of rainfall in a calendar year, he said.

The sprinkling came after more than a month of no rainfall that spurred the Mendocino County Board of Supervisors to declare a drought emergency at its first meeting of the year.

"The rain you got Saturday is not going to do anything in terms of the current drought," Tonkin said. "It may moisten up the grass so that there is not quite as much fire danger, but the creeks won't rise."

The drought that has dried up tributaries, springs and private wells throughout Mendocino County, is threatening water supply in many areas and has spurred the NWS to issue a Red Flag Warning for "increased fire danger above 2,000 feet" for inland and southeastern Mendocino County and Lake County.

The second driest year is 2013, with about 11 inches of rainfall, he said. Not far behind is 2008 with 14 inches, according to Tonkin, who added that the next driest year on record is 1976.

Saturday's rain won't make a dent in local drought conditions, but neither would a normal amount of rain through spring, according to Gregory Jones, a professor in the Department of Environmental Studies at Southern Oregon University.

"If we start to get a more normal amount of rainfall ... through April and May, it's never going to be enough to make it up, unless there's some extreme event that no one can predict," Jones said.

There isn't even a chance of rain on the horizon for Inland Mendocino County in the coming week, according to the NWS, and Jones says long-term weather pattern prediction doesn't hold much hope, either.

"For California, it doesn't look likely," he said, talking about a normal winter weather pattern that's sticking around longer than usual and blocking the Pacific Northwest's regular flow of storms.

If the high-pressure ridge that's pushing the storms north of California and Oregon breaks up and allows more rainfall, spring could come later than normal and be a bit colder, but not dramatically so, according to Jones. He said there is a chance that the fall of 2014 could see a more normal weather pattern for the Pacific Northwest.

What's causing the dry conditions across the West Coast is a tendency he says he's seen over the last 10 to 15 years for the jet stream that would normally be bringing in storm systems from the northeast to slow down and "meander."

As it circles the northern hemisphere from west to east, the jet stream normally also travels north and south, but in a more gradual, gentle pattern than what those who study climate are seeing now, according to Jones. He said the jet stream looks now like a sharp zig-zag line around the globe, and travels north and south in much steeper arcs.

"Climate is so complex," Jones said, "but we couldn't have this happen without a large-scale warming in the Arctic."

That's caused the difference in temperature between the Arctic and sub-tropic regions to shrink, he said. Like a river on relatively flat ground, that creates ideal conditions for the jet stream to wander farther north and south, he said, slowing it and making weather systems stay in place longer.

The result is that low-pressure systems are pushed up over the high-pressure ridge and north to Washington and Canada, he said, and then pulled in a "horseshoe shape" south and east across the United States.

"We tend to see this every winter, but it's usually short-lived," Jones said. "If it breaks down, we will see more normal storms."

In a recent e-mail forecast, Jones wrote, "My scientific sense, and gut feeling, is for a cooler than normal second half of winter, with normal precipitation and snow, but nowhere near enough to catch up in most places."

Tiffany Revelle can be reached at udjtr@ukiahdj.com, on Twitter @TiffanyRevelle or at 468-3523.